Car coupler



May 24, 1955 w. J. METZGER 2,709,007

CAR COUPLER Filed Nov.` 3. 1949 4 Sheets-Sheet l lll I FE. 2o.

IN VEN TOR.

WILLIAM u. rz ER QQ M May 24, 1955 w. J. Ml-:TzGER CAR COUPLER 4Sheets-Sheet 2 Filed Nuv. 3. 1949 INVENTOR.

WILLIAM J. METZGER "ATTORNEY Mlay 24, 1095945 w, J, METZGER 2,709,007

v CAR coUPLER Filed NGV. 3. 1949 4 Sheets-Sheet 3 INVENTOR. WILLIAMWETZGER WM @f M A T TOF/VE Y May 24, 1955 w. J. METZGER 2,709,007

CAR COUPLER Filed Nov. 3. 1949 4 Sheets-Sheet 4 INVEN WILLIAM J. METZG.

A TTRNE Y United States Patent O National Malleable and Steel CastingsCompany,

Cleveland, Ohio, a corporation of Ohio `Application November s, 1949,serial No. l125,323

9 claims. (c1. 213-146) This invention relates to a railway car coupler,and more particularly to anti-creep means forthe lock and to an`improved lock operating'and knuckle throwing mechanisrn.

In the past, the vcoupler lock anti-creep mechanisms Vwere directedprimarily to preventing undesired upward creeping or movement of thecoupler lock due to the bouncing or vertical movements of the coupler inservice. It has been found however, that such mechanisms generallyfailed to prevent the lock from moving to unlocked position underservice conditions where the, coupler was subjected to the combinationof end or 'buiiing shock and vertical shock, such as occurs during asudden run in of slack betweencars having drooped couplers. Such acondition may cause suiiicient rotation of .the lock operating mechanismto release momentarily the. anti-creep so that uponthe vertical shockimparted to the coupler, the lock will be thrown upwardsto .unlockedposition.

My invention provides a lock operating mechanism which serves to preventunlocking of the lock even under the above named condition `of combinedend and vertical shock applied Vto the coupler. The inertia of the lockis utilized under such conditions to assure that the anticreep willremain effective to preclude unlocking of the lock. However, duringdesired actuation of the uncoupling mechanism, the anti-creep ispositively released with an accelerated motiony to permit movement ofthe lock to unlocked position. A feature of the lock operating mechanismis the provision of an arrangement for unlocking the lock and moving theknuckle to open position with a minimum of rotational movement of theuncou.- pling rod. A further feature of the inventionresides in theprovision of improved contact between the lock leg andthe knucklethrower to increase the power Vapplied to the thrower during the knucklethrowing operation.

Ctherfeatures. anduadvantages of the .invention will be set forth in.the following description taken in conjunction with the drawings inwhich:

Fig. 1 is a longitudinal vertical sectional view of a coupler embodyingthe. invention, showing the parts in locked position.

Fig. 2 is atransverse vertical sectional View taken along line 2-2 ofFig. 1.

Fig, 2a is a `detail view of the lock lifter link.

Fig. 3` is a partial view in longitudinal vertical .section showing theanti-creep moved out of active position by the actuation of the rotorlever.

Fig. 3a is a fragmentary sectional view taken along line .3a-3a of Fig.3.

' Fig, 4 is a ,partial view in longitudinal vertical section showing thelock in lock-set positiomwithv the other parts in reposed position.

Fig. Sis a partial view in longitudinal vertical section showing `thelock leg in engagement with the knuckle thrower during the process ofopening the knuckle.

` Fig. V6 is` al partial view 'similar to Fig'. 5 butl showing thepartsl in ffull knuckle thrown position.

`Fig. 7 is a partial View, corresponding to Fig. 1, show- 2,709,007Patented May 24, 1955 ICC ing the anti-creep vengaged to precludefurther upward movement of the lock.

Fig. 8 is a partial view in longitudinal vertical section showing theanti-creep engaged under the conditions of combined end and verticalshock applied to the coupler.

Fig. 9 is a horizontal sectional view showing the parts in lockedposition.

Figs. 10 and 11 are side and end view details of the rotor member.

Fig. 12 is a detailof the rotor lever and also illustrates the end ofthe lever in its relative position at the beginning of the knucklethrowing operation, and in its relative position when the knuckle is inopened position.

Fig. 13 is a fragmentary sectional View taken along line 13-13 of Fig.2.

Fig. 14 is a fragmentary sectional view taken along line 14-14 of Fig.5. v

Fig. 15 is a fragmentary sectional view taken along line 15-15 of Fig.1.

Referring to the drawings, the coupler comprises a head 10 and a knuckle12 which is pivotally connected to the head by means of the usual pivotpin 14. The knuckle comprises a tail portion 16 which, when the knuckleis in closed position, extends into a chamber 18 in the coupler head.Tail 16 may be formed with a vertical lock engaging face 20 and alaterally extending projection or shelf 22. The knuckle is held inclosed position by a lock 24 which in locked position rests on shelf 22and engages face 2i? on the knuckle tail, and wall 26 on the couplerhead. A chamber 28 is provided in the coupler head above the lock 24 forreceiving the lock during lifting thereof to permit opening of theknuckle. The lock has a depending portion or leg 30 which extends intoan opening 32 in the lower portion of the coupler head.

Within opening 32 and lying adjacent lock leg 30, isV

the lock lifter link 34, which is pivotally and slidably connectedv tothe lock leg by means of a trunnionA 36 which is received in an upwardlyand rearwardly sloping slot 38 in the lower portion of the leg. Lifterlink 34 is formed with an anti-creep arm 40 which extends upwardly fromtrunnion 36 and underlies shelf 22. The upper end of arm 40 ispreferably rounded and is adapted to engage the underside 41 of shelf 22in the event that lock 24 creeps upwardly or is accidentally bouncedupwardly to limit further movement thereof. ward portion of surface 41is curved downwardly as at 41a to make the anti-creep more effective.Link 34 also has a downwardly extending arm 42 which is received in thebifurcated forwardly extending portion 44 of rotor lever 46 and ispivotally connected thereto by means of a pin 48. As may be seen in Fig.l, link 34 occupies a substantially vertical position with trunnion 36disposed directly above pin 48 when the coupler parts are in normallocked position.

The rearward end 5i) of lever 46 is pivotally connected to the undersideof the coupler head by means of a rotor member 52 which is mounted inthe spaced depending flanges 54 and 56 on the coupler head. It will beobserved that the axis of member 52 is disposed at an elevationintermediate that of trunnion 36 andpivot pin 48. It will be also notedthat the distance from the axis of pin 48 to the axis of member 52 aboutwhich lever 46 rotates, is substantially greater than the distance fromthe airisy of pin 48 to the axis of trunnion 36. This relationship ofthe parts in conjunction with the disposition of trunnion 36 directlyabove pin 4S assures 'a quick withdrawal of anti-creep arm 4t)rearwardly from beneath shelf 22 as lever 46 is rotated to raise thelock,

Rotor member 52 as may best be seen in Figs. l0 and 11, comprises a keyportion 58 which is received in a corresponding opening in portion S0 ofthe rotor lever,

The rearand cylindrical bearing portions 60 and 62 which are adapted tobe received in anges 54 and 56 respectively. Bosses 64 and 66 are formedon the inner side of flanges S4 and 56 to provide increased bearingareas for cylindrical portions 60 and 62. Rotor member 52 is providedwith a flange 68 which, when the coupler parts have been assembled, isdisposed between flange S4 and a retaining flange 70, thereby preventingthe rotor member from being displaced axially from its normal position.An eye portion 72 is provided at the end of the rotor member forreceiving the hooked end of an uncoupling rod 74 (shown in dot-dash).

The operation of the parts to effect intentional unlocking of thecoupler will now be described. Starting with the coupler parts in normallocked position as seen in Fig. l, as rotor member 52 is rotated throughactuation of the uncoupling rod, rotor lever 46 is caused to pivot in aclockwise direction. The initial pivotal movement of lever 46 moves thelower end oi arm 42 forwardly and upwardly and simultaneously therewith`moves trunnion 36 rearwardly and upwardly to the upper or rearward endof slot 33 in the lock leg as seen in Fig. 3. This operation serves tomove the upper arm 40 from beneath shelf 22 on the coupler tail toinactive position by an accelerated motion. lt will be observed thatduring this movement, link 34 not only pivots about trunnion 36, but iscammed upwardly and rearwardly through the action of slot 38. Thus for agiven amount of rotation of the rotor lever 46, a substantial withdrawalrearwardly of arm 48 is effected. The lock is now free to be moved tounlocked position, and upon rotation of lever 46 from its position inFig. 3, an upward and rearward force is directed by trunnion 36 againstthe lock leg. Since the lock leg is normally in engagement with rearwall 7S of opening 32, the initial movement of the lock is verticallyupwards. However, after the lock is raised to the position wherein leg3i) is clear of wall 75, then the leg is moved both upwardly andrearwardly until shoulder 76 is above arm 78 of the knuckle thrower,after which upon release of the uncoupling rod, the lock will besupported by shoulder 76 resting on arm 78. This is the lockset positionas shown in Fig. 4, in which the parts are shown at rest, with trunnion36 occupying the lower end of slot 38. As the lock is actuated furtherfrom the lockset position, the surface 80 of the lock leg now moves intocontact with arm 78 of the knuckle` thrower. ln Fig. 5, surface Sil hasjust come into contact with arxn 78. Rotation of lever 46 from thisposition continues to urge the lock upwardly until fulcrurn lug 82 onthe lock engages abutment 83 in the coupler head. Thereafter, the lockpivots about abutment 83 and lock leg 3i) moves arm 78 rearwardly,thereby rotating the knuckle thrower and effecting pivoting of theknuckle toward open position through the action of arm 84 at the otherend of the thrower against pad 85 on the knuckle. As rotation of lever46 continues, the lock pivots a predetermined amount about abutment 83until the top portion S6 of the lock moves into engagement with asecondary pivot pointy 88 disposed about abutment 83, whereupon the lockpivots about the point 8S as the knuckle throwing operation progresses.A guide rib 89 serves to pre vent the upper end of the lock from slidingforwardly during this operation. lt will be apparent that the force nowdirected by the lock leg against arm 78 will be more nearly in ahorizontal direction, as compared with its direction when the lockpivots about abutment 83, thereby exerting a greater' effective forceagainst the knuckle thrower during the final movement of the knuckletoward open position. As rotor lever 46 is rotated, the lock continuesto pivot about portion 88 until the knuckle is fully thrown open as seenin Fig. 6. This secondary fulcrum action constitutes a feature of thelock operating mechanism.

lt will be observed that during the unlocking operation when trunnion 36occupies the upper or rearward end of slot 38, as seen in Fig. 3, it isdisposed rearwardly of pin 48 and therefore a rearward as well as anupward force is imparted by the trunnion to the lock ieg duringactuation of the link by the rotor lever. In addition, the center ofgravity of the lock is forward of the line of force passing through pin48 and trunnion 36, thus tending to swing the lock leg rearwardly whenthe trunnion is in the upper end of slot 38 and the lock is being liftedthereby. This action becomes of considerable importance in the event thelock leg in service becomes displaced forwardly in engagement with frontwall 90 of opening 32. In such a case as rotation of lever 46 movestrunnion 36 into engagement with the upper end of slot 38 the trunnionremains disposed rearwardly of pin 48 and also the center of gravity ofthe lock still remains forward of the line of force passing through pin48 and trunnion 36, thus assuring that the initial movement of the lockleg is rearward until it engages rear wall 75, as seen in Figs. 1 and 3.This permits arm 40 to be swung from beneath shelf 22 upon furtherrotation of lever 46, thereby releasing the anticreep to the lock. Thusthe mechanism initially provides for positive rearward movement of thelock leg upon actuation of the rotor lever so that the anti-creep willbe released under all possible positions of the lock leg in opening 32.

In Fig. 7 is shown the manner in which arm 40 of lock lifter link 34cooperates with surface 41 on the knuckle tail to limit upward creepingor accidental upward movement of the lock in service. The lock has beenmoved bodily upwards until the upper end of arm 40 engages surface 41thereby preventing further upward movement of the lock. In this positiontrunnion 36 occupies the lower end of slot 38 as in reposed position ofthe parts (Fig. 1). Consequently any movement of arm 40 rearwardly fromthe position shown in Fig. 7 will necessitate downward movement of thelock due to the camming action of trunnion 36 in slot 38 as the linkpivots about pin 48. In addition, the downward curvature of surface 41,at 41a, serves to increase the amount of downward movement of the lockin order that arm 40 can be moved from beneath surface 41a. It is thusseen that upward movement of the lock to the position in which theknuckle can be opened is effectively prevented.

In Fig. 8 is illustrated the manner in which the anticreep functions tolimit upward movement of the lock under the conditions of combined endand vertical shock that may occur in service, for example, during a lrunin of slack between cars having drooped couplers. Under this condition,the end shock will cause the lock leg to move forwardly into engagementwith front wall 90 of opening 32 and rotor lever 46 may be caused torotate until trunnion 36 of the lifter link is raised to the upper endof slot 38. Normally when the rotor lever is actuated intentionally bymeans of the uncoupling rod and trunnion 36 is displaced to the upperend of slot 38, the end of arm 40 is clear of shelf 22 as seen in Fig.3. However, with the lock displaced forwardly in engagement with frontwall 90, the lifter link cannot be rotated to a position in which arm 40is clear of shelf 22. Therefore, as the vertical shock causes the lockto be raised, a portion of the upper end of arm 40 still remains beneathshell 22 and engages undersurface 41 to prevent further J upwardmovement of the lock. Thus, while rotation of rotor lever 46 under theend shock may cause the upper arm 40 to be rotated rearwardly andtrunnion 36 of the lock lifter link to occupy the upper end of slot 38,simultaneously therewith the inertia of the lock leg causes the latterto engage wall 90 and move the lifter link bodily forwardly to a pointin which arm 40 is partially beneath ledge 22. The clearance provided asat x between front wall 90 and the opposing side of the lock leg, withthe parts in normal locked position as in Fig. 1, is such as to beapproximately equal to the amount of overlap between anti-creep arm andknuckle shelf 22 under the condition of the parts as shown in Fig. 8. Itwill be seen therefore, that even 'under the conditions of combinedendand vertical shock, the lock anti-creep is eective to preclude upwardmovement of the lock to a position in which the knuckle is free to beopened.

A feature of the invention resides in so forming link 34 that upper arm40 in the region of trunnion 36, has its side 92 offset laterally fromthe side 93 of lower arm 42, so that the upper surface of the trunnionis increased `in lateral extent as at 94. The lock leg is provided witha lateral projection 95 which extends the upper surface of the upper endof sl'ot 38 and thereby is adapted to engage surface 94 of the trunnionduring operation of the mechanism to unlock the coupler, as in Fig. 3a.in addition to reducing wear on the trunnion and slot engaging surfaces,also relieves the trunnion of a substantial amount of shearing stress,since during raising of the lock with portion 94 ofthe trunnion engagingprojection 95, lower arm 42 is subjected to a direct cornpressive force.The increased lateral extent of trunnion 36 also servesto stabilize thelock during raising of the latter by the actuation of the uncouplingmechanism.

It will be observed that the lower rearward side of the lock leg isrelieved as at96 (Figs. 14 and 15 thereby forming a projection 98 on theouter side of the lock leg on which is located the knuckle throwerengaging surface 80. This assures that the force of the lock leg againstarm 78 of the knuckle thrower will be directed thereto at a point amaximum distance from the pivotal axis of the thrower. Also rear wall 78of the coupler head is recessed as at 100 to receive projection 98 whenthe lock is in locked position, as Seen in Figs. l and l5. In thisposition, a clearance exists between surface 80 of projection 98 and theopposing surface 102 on the coupler head, While surface 96 of the Vlockleg engages rear wall 75. Thus in locked position of the coupler, noWear takes place on surface 80.

Surface 80 is preferably rounded in a horizontal direction so as toprovide improved surface contact with thrower arm 78. Also the lowerportion of surface 80, as at 80a, is formed so as to slope downwardlyand forwardly when the lock is in locked position so that when thissurface is in contact with the knuckle thrower near the completion ofthe knuckle throwing operation, itis disposed approximately in avertical position. This in conjunction with the pivoting of the lockabout pvot point 88 results in the direction of a horizontal force tothe knuckle thrower.

The mechanism, in addition to providing effective anticreep means forthe lock, also operates to unlock and open the knuckle with minimumrotation of the uncoupling rod. Moreover, while the total rotation ofthe rotor lever is kept to a minimum, the portion thereof which occursduring the opening of the knuckle has been increased, resulting in again in leverage which makes for easier operation of the mechanism. InFig. l2, rotor lever 46 is shown in position A wherein the coupler islocked, as in Fig. l. Position B corresponds to the beginning of theopening of the knuckle and position C corresponds to the fully openedposition of the knuckle. Thus, from position B to C the rotor levermoves through an angle of about 251/2 degrees, while the total angle ofrotation is about 84 degrees. The position of the rotor levercorresponding to release of the anti-creep is only about 71/2 degreesfrom position A and therefore is not shown.

The following is a comparison of the angular movement of the rotor lever46 with that of the rotor lever of the existing A. A. R. standard type Htightlock coupler as shown in the 1946 Car Builders Cyclopedia, page918.

This feature l Air-il iis'.

It will be observed from the above that to release the anti-creep of thepresent application requires a rotation olv the yrotor lever of lessthan one-fourth that necessary to release the anti-creep of the existingcoupler. Also it is significant that the rotor lever of the presentapplication rotates several more degrees than that of the. existingcoupler to open the knuckle once this operation begins. Moreover, thetotal rotation of the rotor lever is considerably less than that for theexisting coupler.

To assemble the coupler, the knuckle thrower is rst applied -to thecouplerl head through the front opening thereof. Next the rotor lever 46to which the lock lifter link 34 has previously been connected by pin48, is applied to the head with the link hanging downwards. In thisposition of the rotor lever, rotor member 52 can be inserted throughfranges 54, S6 and the key receiving opening in the rotor lever untilange 68 engages the outer side of depending ange 54 on the head.Thereafter, the lifter link is raised up through the lock receivingopening 32' in the head into a position in which arm 4.0 extendsVthrough the front opening in the head. During the latter operation, therotorlever is pivoted to a position in which flange 68 thereof isbetween retaining flange '70 and dependingange 54. The lock leg is nextentered through the front ot' the coupler and trunnion 36 of the lifterlink is hooked into slot 38 of the lock leg. Then the lock is loweredAinto the lock receiving opening 32, after which it is vraised to thelock set position, with shoulder 76 resting on the knuckle thrower arm7S. The assembly is completed with the application of knuckle 12 to thehead.

Disassembly of the coupler is accomplished by performing each of theabove steps in reverse order.

The'terms and expressions which I have employed are used as terms ofdescription and not of limitation, and I have no intention, inthe use ofsuch terms and `expressions, of excluding any equivalents of thefeatures shown and described or portions thereof, but recognize thatvarious modifications are possible within the scope of the inventionclaimed.

What I claim is:

l. fIn a car coupler having ahead and a knuckle pivoted to said head,said knuckle having a tail, a vertically movable lock for said knuckle,said lock having a leg extending downwardly rthrough an opening in saidhead, said opening having front and rear walls so spaced apart as to`provide clearance `for limited movement of said lock leg longitudinallyof the coupler, a rotor lever pivoted to theunderside of said head, anda lock lifter link having a trunnion intermediate its ends, said leghaving an elongated slot extending upwardly and rearwardly, saidtrunnion being received in said slot and normally occupying the lowerend thereof, said link having its lower end connected to said lever at apoint substantially directly below said trunnion, said link connectionsand said slot being so arranged that with said trunnion in the lower endof said slot the upper end of said link underlies a portion of saidtailwhen said lock leg is disposed against said front wall or againstsaid rear wall of said opening, and with said trunnion in the upper endof said slot the upper end of said link underlies a portion of said tailonly when said lock leg is in engagement with said front wall of saidopening.

2. In a car coupler having a head and a knuckle pivoted to said head,said knuckle having a tail, a vertically movable lock for said knuckle,said lock having a leg extending downwardly through an opening in saidhead, a rotor lever pivoted to the underside of said head, and a locklifter link having a trunnion intermediate its ends, said linkcomprising a lower arm and an upper arm, said lower arm being pivotallyconnected to saidlever, the upper end of said lower arm having a portioncurved to correspond with the upper surface of said trunnion and formingan extension thereof, said upper arm extending upwardly from said lowerarm adjacent said curved portion and underlying a portion of said tail,said lock leg having a slot for receiving said trunnion, said lockhaving a projection on a side thereof and forming an extension of theupper surface of said slot for engagement with said curved portion onsaid lower arm during actuation of said lever to raise said lock.

3. In a car coupler having a pivoted knuckle and a movable lock, saidknuckle having a tail, a lock operating mechanism comprising a rotorlever pivoted to said coupler, and a lock lifter link having its lowerend pivoted to said lever, the upper vend of said link normallyunderlying a portion of said tail, a laterally extending trunnionintermediate the ends of said link, a side of the upper portion of saidlink being Offset laterally from the corresponding side of the lowerportion of said link to provide an extension of the upper side of saidtrunnion surface, said lock having a leg formed with an opening toreceive said trunnion, said leg having a lateral extension providing acontinuation of the upper surface of said opening, said trunnion surfacebeing adapted to engage said surface on said lateral extension of saidlock leg during actuation of said lever to raise said lock.

4. A lock lifter link for a car coupler, said link comprising a lowerarm adapted for pivotal connection to 'a rotor lever, an upper armextending upwardly from said lower arm and adapted to underlying aportion of a coupler knuckle to form an anti-creep for the lock, and alaterally extending trunnion at the juncture of said upper and lowerarms adapted to be received in a slot in tne lock leg, said upper armhaving a side offset laterally from the side of said lower arm toprovide an extension of the upper surface of said trunnion, saidextension of said trunnion surface being adapted for engagement with alateral extension of the surface of the slot in said lock leg duringactuation of the rotor lever to raise the lock.

5. A lock lifter link for a car coupler, said link comprising a trunnionportion adapted to be received in a slot in the leg of the coupler lock,an arm extending upwardly from said trunnion portion and being adaptedto underlie a portion of a coupler knuckle to form an anti-creep for thelock, and another arm extending downwardly from said trunnion portionadapted for pivotal connection to a rotor lever, said lower arm beingwider adjacent said trunnion than said upper arm, said widened portionof said lower arm providing an extension of the upper surface of saidtrunnion, said extension of said trunnion surface being adapted forengagement with a lateral extension of the surface of the slot in thelock leg during actuation of said rotor lever to raise the lock.

6. In a car coupler having a head and a knuckle pivoted to said head,said knuckle having a tail, a vertically movable lock for said knuckle,said lock having a leg extending downwardly through an opening in saidhead,

a rotor lever pivoted to the underside of said head, and a lock lifterlink having a trunnion intermediate its ends, the lower end of said linkbeing pivotally connected to said lever, the upper end of said linkunderlying a portion of said tail, said leg having an upwardly andrearwardly extending elongated slot for receiving said trunnion, saidslot being so disposed that upon initial rotation of said lever thecamming action of said slot against said trunnion withdraws the upperend of said link from beneath said shelf with an accelerated motion,said lock leg normally engaging the rear wall of the opening in saidhead when said knuckle is in closed position and being spaced rearwardlyfrom the front wall of the opening, said leg being adapted to moveforwardly into engagement with said front wall upon the application ofan end shock to the coupler, in which position the camming action ofsaid slot against said trunnion is ineffective to withdraw the upper endof said link entirely from beneath said shelf portion,

7. in a car coupler having a head and a knuckle pivoted to said head,said knuckle having a tail, a vertically movable lock for maintainingsaid knuckle in closed position, said lock having a leg extendingdownwardly through an opening in said head, said opening having frontand rear walls spaced apart a predetermined amount to provide clearancefor movement of said lock leg longitudinally of the coupler, a rotorlever pivoted to the underside of said head, and a lock lifter linkhaving a horizontal trunnion intermediate its ends, said leg having anelongated slot extending upwardly and rearwardly, said trunnionextending into said slot and occupying the lower end thereof when saidknuckle is in closed position and the parts are at rest, the lower endof said link being pivotally connected to said lever, the upper end ofsaid link underlying a portion of said tail for all positions of saidlock leg in said opening in a direction longitudinally of the couplerand being adapted to be withdrawn from beneath said tail portion uponintentional actuation of said lever, said leg upon the application of anend shock to the coupler being adapted to move forwardly into engagementwith said front wall, in which position actuation of said lever isineffective to withdraw the upper end of said link entirely from beneathsaid tail.

8. A lock for the knuckle of a car coupler, said lock comprising adepending leg adapted to extend downwardly into an opening in thecoupler, said leg having an elongated transverse slot extending upwardlyand rearwardly, said slot being adapted to receive a trunnion of anassociated lock lifter link and having a surface in its upper end forengagement by said trunnion, said leg being formed with a lateralprojection adjacent the upper end of said slot which provides acontinuation of said surface in the upper end of the slot.

9. A lock constructed in accordance with claim 8 in which saidprojection is formed on the side of said leg facing the associated link.

References Cited in the le of this patent UNITED STATES PATENTS2,083,422 Bazeley June 8, 1937 2,217,722 Bazeley Oct. 15, 1940 2,340,818Metzger Feb. l, 1944 2,350,470 Metzger June 6, 1944 2,393,912 KaylerJan. 29, 1946 2,585,958 Metzger Feb. 19, 1952

